Well there you go! The reason the 7D2 has been delayed so long is that it will be a full frame mirrorless dual pixel quad pixel fovenon big megapixel camera with a 1DX build in an EOS-M package.... that will shoot at ISO 819,200 and take 8K video.....

This is widely stated, but I can't see that the EF-M mount is much different in dimensions to the Sony E mount; I know that E mount is tight for full frame, but it is still possible. I'm struggling to find the technical specifications, but here's a comparison (assuming the scaling is correct) -measure for yourself:

EF-M is pretty similar to E-mount in its internal diameter and a bit larger than either X-mount or micro 4/3rds. We also know that the flange back distance is the same as E-mount (18mm, vs 44mm for regular EF).

I'm not saying that this proves EF-M is compatible with full frame sensors, nor that Canon would have any near term plans to produce a full frame mirrorless camera if it were, but it would be a bit strange if they happened to make it so similar in size to E-mount and it not be FF capable. They must have had some idea that Sony were interested in making a FF E-mount camera. I believe that FF probably is possible with EF-M mount, if nothing else then to cover that base for the future. Of course, Canon would never admit that now whilst it is still trying to push their FF DSLRs!

As for a mirrorless camera with an EF mount: it's possible but not with a reduced flange back distance, or they'd create all sorts of lens compatibility confusion!

Thus either this rumor is a hoax (why would Canon not want to reduce the cost of sensors made for the top end?)...

Can I flip this around: why would the top end be the priority for reducing production costs? Surely the margins are tighter at the bottom? Besides, I can't think of why a new production technology that improves yield wouldn't equally benefit APS-C sized sensor production costs.

I think that this whole rumour is based upon the "all cameras will be full frame in the future" fallacy that we're now meant to buy into. If Canon are experiencing pressure from mirrorless in the APS-C market, then it's lenses that are more to blame than camera bodies.

This is widely stated, but I can't see that the EF-M mount is much different in dimensions to the Sony E mount; I know that E mount is tight for full frame, but it is still possible. I'm struggling to find the technical specifications, but here's a comparison (assuming the scaling is correct) -measure for yourself:

EF-M is pretty similar to E-mount in its internal diameter and a bit larger than either X-mount or micro 4/3rds. We also know that the flange back distance is the same as E-mount (18mm, vs 44mm for regular EF).

I'm not saying that this proves EF-M is compatible with full frame sensors, nor that Canon would have any near term plans to produce a full frame mirrorless camera if it were, but it would be a bit strange if they happened to make it so similar in size to E-mount and it not be FF capable. They must have had some idea that Sony were interested in making a FF E-mount camera. I believe that FF probably is possible with EF-M mount, if nothing else then to cover that base for the future. Of course, Canon would never admit that now whilst it is still trying to push their FF DSLRs!

As for a mirrorless camera with an EF mount: it's possible but not with a reduced flange back distance, or they'd create all sorts of lens compatibility confusion!

According to Canon's full frame white paper, the diagonal measurement of a FF sensor is 43.3mm The measured inner diameter of the lens mount opening on the EOS M, accounting for the bayonet protrusions, is 43mm. For comparison, the measured inner diameter for the EF mount opening is 51mm.

Having said that, the Sony a7 mount opening appears to 'clip the corners' of the sensor, and is quite similar in size to the EOS M's opening.

Before people get too excited, they might want to re-read this CR-1 rumor.

It is focused on improvements in manufacturing technology to increase yields and reduce costs. Aside from a glancing mention of "Foveon Like" technology (whatever that is supposed to mean), this is all about reducing costs of production, not about any change in the performance of sensors.

That's not to say it isn't important or beneficial to consumers, just that the benefits are more likely to come in some combination of lower costs and better margins.

Thus either this rumor is a hoax (why would Canon not want to reduce the cost of sensors made for the top end?)...

Can I flip this around: why would the top end be the priority for reducing production costs? Surely the margins are tighter at the bottom?

I believe that you're thinking it wrong: ANY reduced manufacturing costs goes straight to the bottom line.

Sure, the lower end has a higher volume, but sometimes it is easier to reduce costs at the high end simply because people didn't bother too much about cost, with the argument that "it's high end, so our focus is quality, not cost", which ends up in a circular argument resulting in high cost.

This is widely stated, but I can't see that the EF-M mount is much different in dimensions to the Sony E mount; I know that E mount is tight for full frame, but it is still possible. I'm struggling to find the technical specifications, but here's a comparison (assuming the scaling is correct) -measure for yourself:

EF-M is pretty similar to E-mount in its internal diameter and a bit larger than either X-mount or micro 4/3rds. We also know that the flange back distance is the same as E-mount (18mm, vs 44mm for regular EF).

I'm not saying that this proves EF-M is compatible with full frame sensors, nor that Canon would have any near term plans to produce a full frame mirrorless camera if it were, but it would be a bit strange if they happened to make it so similar in size to E-mount and it not be FF capable. They must have had some idea that Sony were interested in making a FF E-mount camera. I believe that FF probably is possible with EF-M mount, if nothing else then to cover that base for the future. Of course, Canon would never admit that now whilst it is still trying to push their FF DSLRs!

As for a mirrorless camera with an EF mount: it's possible but not with a reduced flange back distance, or they'd create all sorts of lens compatibility confusion!

According to Canon's full frame white paper, the diagonal measurement of a FF sensor is 43.3mm The measured inner diameter of the lens mount opening on the EOS M, accounting for the bayonet protrusions, is 43mm. For comparison, the measured inner diameter for the EF mount opening is 51mm.

Having said that, the Sony a7 mount opening appears to 'clip the corners' of the sensor, and is quite similar in size to the EOS M's opening.

So with the Sony a7r, do the clipped corners affect the image in anyway? Surely not since no one has reported black corners. How does that work then? Is the entire sensor area not used then? That would mean in reality a sensor size slightly smaller than FF, prob negligible though overall?

If that's the case then perhaps a FF sensor could be squeezed into the M mount then with a tiny bit of cropping. Or Canon could make a completely new sensor that is almost FF in size and fits perfectly (seems unlikely in terms of maximizing profits).

Thus either this rumor is a hoax (why would Canon not want to reduce the cost of sensors made for the top end?)...

Can I flip this around: why would the top end be the priority for reducing production costs? Surely the margins are tighter at the bottom?

I believe that you're thinking it wrong: ANY reduced manufacturing costs goes straight to the bottom line.

Sure, the lower end has a higher volume, but sometimes it is easier to reduce costs at the high end simply because people didn't bother too much about cost, with the argument that "it's high end, so our focus is quality, not cost", which ends up in a circular argument resulting in high cost.

Believe me, I speak from experience (sigh).

1. What yield improvement were you thinking of that is of no benefit to APS-C sized sensors?

2. If it is of benefit to APS-C sized sensors, why apply it only to full frame sensors? Surely you apply the technology that improves yield to the production line that has the highest production levels (i.e. APS-C), not the one with the lowest?

Well there you go! The reason the 7D2 has been delayed so long is that it will be a full frame mirrorless dual pixel quad pixel fovenon big megapixel camera with a 1DX build in an EOS-M package.... that will shoot at ISO 819,200 and take 8K video.....